Problems getting around may be early Alzheimer's indicator

By Stephen Feller   Having trouble figuring out where to go may be an early sign of Alzheimer's disease, based on a recent study linking the ability to get through a maze to other biomarkers indicative of it.

Researchers at Washington University in St. Louis compared the ability to navigate a maze by groups of people with and without biomarkers for the development of Alzheimer's disease, finding it accurately predicted whether they were at risk for the disease.

Preclinical Alzheimer's disease indicates changes in the brain related to the disease and can be detected by testing for biomarkers in the brain and spinal fluids. The biomarkers can predict the development of plaques in the brain affecting the hippocampus and caudate.

Both the hippocampus and caudate are involved with route learning, cognitive map building and direction, making finding one's way through a computerized maze a theoretically decent measure of function. Based on the results of their recent study, the researchers think they have a reliable indicator for causes of the disease.

"This pattern is consistent with decrements in hippocampal integrity prior to changes in the caudate," Dr. Denise Head, an associate professor of psychological and brain sciences at Washington University in St. Louis, said in a press release. "These findings suggest that navigational tasks designed to assess a cognitive mapping strategy could represent a powerful tool for detecting the very earliest Alzheimer's disease-related changes in cognition."

For the study, published in the Journal of Alzheimer's Disease, researchers recruited 42 clinically normal people without biomarkers for Alzheimer's, 13 people who tested positive for the markers and 16 people with behavioral symptoms indicative of early Alzheimer's disease.

The participants spent two hours on a computer testing their abilities on a virtual maze, specifically how well they could learn and follow a pre-set route, and how well they could form and use a cognitive map of the maze.

The group with pre-clinical Alzheimer's performed worse on the tasks in comparison to the normal group, but overcame difficulties and performed almost as well as the normal individuals.

"These findings suggest that navigational tasks designed to assess a cognitive mapping strategy could represent a powerful new tool for detecting the very earliest Alzheimer's disease-related changes in cognition," Head said. "The spatial navigation task used in this study to assess cognitive map skills was more sensitive at detecting preclinical Alzheimer's disease than the standard psychometric task of episodic memory."